I feel like that’s higher than the actual livable and free lifetimes the average person has.

It’s a part of the header sent with every internet request. Standard thing to identify the user’s language so you know which version to send

While that’s true, there’s also the “Works on my machine” effect.

It might’ve been less obstructive on their pc than on op’s

Federated means that any instance that is federated with them receives their content and can bee seen on that instance.

Defederated means they are not federated anymore, thus blocking both users and content.

It’s usually done to combat content you don’t want on your instance